Fiyaz Mughal, director of the Faith Matters counter-extremism group, said the prison term should have been fully served. “Choudary’s early release sends out a message of weakness within our state,” he told The Independent.

“It is a slap in the face of many people, including many Muslims who have been, for two decades, saying that action needed to be taken against him for the poisoning of young minds.

“Choudary has been the inspiration for many young people who have then decided to take up violent jihad, and this man has been one of the nexus points of extremism in our country.

“With individuals like him, who are a nexus of extremism, a sentence should mean a sentence that is served out.”

The 51-year-old preacher was held at a separation unit for extremists at HMP Frankland for part of his sentence, in a bid to prevent him radicalising fellow inmates.

The National Probation Service, police and MI5 have collaborated on a package of strict licence conditions aimed to stop Choudary continuing his previous activities.

A lengthy list of conditions imposed upon him was expected to include electronic monitoring, heavily restricted internet access and communications, and bans on associating with fellow extremists, speaking publicly, holding meetings or entering exclusion zones.